Rotor construction



June 20, 1961 E. P. wARNKl-:N 2,989,285

ROTOR CONSTRUCTION Filed Sept. 18, 1958 FIG@ \m\ 39 FIG. 5.

ul ll ."lll Il Nl Unmk g fFIG.

INVENTOR. ELMER P. WARNIKEN BWM@ ATTORNEYS States Patent 2,989,285 ROTOR CONSTRUCTION Elmer P. Warnken, Cincinnati, Ohio, assignor to Studebaker-Packard Corporation, South Bend, Ind., a corporation of Michigan Filed Sept. 18, 1958, Ser. No. 761,764 Claims. (Cl. 253-77) This invention relates to rotor construction and' more particularly to construction of blade-carrying rotor wheels for air compressors and the like.

It is considered advantageous in certain applications such as the compressor section of gas turbine engines to fabricate blade-carrying rotors from reinforced plastic material. Such rotor wheels are characterized by relatively large peripheral and Ehub portions and joined by a relatively thin intermediate section. The enlarged periphery is necessary to support the air foil blades, and `the intermediate portion is required to be thin to reduce centrifugal stresses created during rotation of the unit. Prior to the present invention it has been difficult to fabricate rotor wheels of such configuration because of inherent limitations in the molding of reinforced plastic structures, it being difficult to mold the wide overhang of the hub and the periphery.

In view of the foregoing state of the art, it is an objective of the present invention to provide a rotor wheel formed of two matching discs in which the portion of each disc between the hub and the periphery is of reduced cross sectional thickness.

It is a further object of the present invention to provide a rotor construction fabricated from a plurality of discs, each of which can be readily molded from reinforced plastic materials.

It is a still further object of the present invention to provide an air foil blade having a root shape which is readily assembled to a twin disc rotor and in which means are provided for locking the blade between said discs.

These and further objects and features of the present invention will be apparent to those skilled in the art from the following description and the accompanying drawings in which:

FIGURE l is a plan view of a rotor construction in accordance with an embodiment of this invention;

FIGURE 2 is a sectional view in elevation taken along section line II-II of FIGURE l;

FIGURE 3 is a perspective View showing one of the rotor blades;

FIGURE 4 is an exploded perspective view showing the discs of the rotor wheel and a hub member on which the discs are mounted;

FIGURE 5 is a longitudinal section showing the rotor operably mounted in an air compressor; and

FIGURE 6 is a sectional view taken along section line VI-VI of FIGURE 4.

In the following detailed description and the drawing like reference characters indicate like parts.

In FIGURES l and 5 is shown a rotor wheel 10 which carries a plurality of rotor blades 12. The rotor 10' can be mounted on a shaft 13 (FIGS. 2 and 5) inside an appropriate housing 14 (FIG. 5).

As shown in FIGURE 3, each blade 12 includes a main or airfoil section 16 and a root section 17. The root section is enlarged, as shown, and lugs 18 (only one of which is shown in FIGURE 3) are formed on opposite sides of the central portion of the root end section. Ends of lugs 18 terminate short of the ends of root sections.

As shown most clearly in FIGURES 2 and 4, the rotor wheel includes two discs `19 and 21. 'Ihe discs 19 and 21 have central openings 22 and 23 respectively, through which a thimble 24 extends. The thimble 24 has exterice nal knurling 26 which engages the discs 19 and 21 to cause them to turn together and with the thimble 24.- The thimble 24, in turn, is mounted on the shaft 13. A nut (FIG. 2) mounted on the shaft holds disc 19 in engagement with a flange 27 of the thimble and holds the flange 27 of the thimble against a shoulder 28 of the shaft 13. A washer 29 mounted onfthe shaft 13 engages the disc 21.

The discs are intended to be molded of appropriate plastic material such as fiber glass reinforced phenolformaldehyde materials, or may be formed of metal or other suitable material.

rIhe lower disc 21 has a hub section 30 which receives a portion of the thimble 24, an intermediate section 31 of reduced thickness, and an outer section 32 of full thickness. The outer section is provided with a plurality of slots 33, each of which receives the lower half of root end portion of one yof the blades.

Details of construction of one of the slots 33 are shown in FIGURE 6. The slot 33 includes a lower portion 34 of a size to receive a main portion of the root end section 17of one of the blades. The slot 33 also includes enlarged sections 36 and 38 which intersect a face 39 of the disc. Each of the enlarged sections 36 and 38 receives one-half of one of the lugs 18 of the root end section of one of the rotor blades. The upper disc-is generally similar in construction to the lower discV 21. The upper disc 19 is provided with slots 41, each of which receives an upper half of the root end section of one of the blades. A face 42' of the upper disc 19 (FIG. 2) whichengages the face 39 of the lower disc, has enlarged slot sections 43 which receive upper portions of the lugs 18.

When the discs and blades are assembled, the root portions 18 of the blades are locked between the discs.

As shown most clearly in FIGURE 2, the intermediate section 31 of the disc 21 is cut away as indicated at 46 and 47 on its opposite faces to reduce the thickness and mass of the intermediate section. Similarly, an intermediate section of the upper disc 19 is cut away as indicated at 48 and 49 on its opposite faces. The cut away sections at the adjacent faces form an annular space between the discs inboard of the outer engaging sections and outboard of the inner or hub sections. As shown, the cutting away reduces the mass of the intermediate sections of the discs substantially without providing any excessive overhangs. The overhangs of the hub sections and outer sections of the rotor discs are of such moderate proportions that the dies can be formed from plastic materials.

It is apparent that the discs 19 and 21 are identical in configuration, they being assembled juxtaposed in a face-to-face relationship. Thus, a single molding and machining setup can be provided to produce the twin disc wheel 10.

The rotor wheel illustrated in the drawing and described above is subject to structural modification Without departing from the spirit and scope of the appended claims.

I claim:

1. A rotor, comprising; a pair of interchangeable discs each having a plurality of slots provided through and axially across the outer peripheral edge thereof, said slots of respective discs being axially alignable, a plurality of rotor blades each including a root section receivable in radially locked engagement within said slots and having a locking projection provided intermediate the ends thereof, and said root sections and slots being cooperatively formed for axial locking engagement of said locking projections between said discs as secured in face engaging relation.

2. A rotor, comprising; a pair of interchangeable discs each having a plurality of slots provided through and axially across the outer peripheral edge thereof in equally spaced relation, said slots of respective discs being axially alignable and enlarged near one end thereof, a plurality of rotor blades each having a root section receivable in radially locked engagement within said slots and including a locking projection provided intermediate the ends thereof and receivable within the enlarged ends of said slots as adjacently disposed and aligned, and means for securing said discs together within the projections of said root sections axially locked therebetween.

3. A rotor, comprising; a pair of interchangeable discs each having a plurality of slots provided through and axially across the outer peripheral edge thereof in equally spaced relation, said slots of respective discs being axially alignable and enlarged near one end thereof, a plurality of rotor blades each having a root section receivable in radially locked engagement within said slots and including locking projections provided on opposite sides of said root sections and intermediate the ends thereof and receivable within the enlarged ends of said slots as adjacently disposed and aligned, said enlarged ends being formed for the close tting reception of said locking projections, and means for securing said discs together with said projections securely held therebetween.

4. A rotor, comprising; a pair of interchangeable discs each having a plurality of slots provided within and axially across the outer peripheral edge thereof, a plurality of rotor blades each having a root section receivable in the slots of said discs as secured together and having said slots aligned, said slots and root sections being cooperatively formed for radial locking engagement of said rotor blades, locking projections provided on opposite sides of said root sections and intermediate the ends thereof, and said slots of at least one of said discs being formed adjacent one face thereof for axial locking reception of said locking projections therein.

5. A turbine rotor, comprising; a pair of interchangeable rotor discs adapted to be secured in faceto-face engaging relation, said discs including enlarged inner and outer peripheral portions providing a reduced annular midsection and a mass reductive space between said discs as secured together, a plurality of turbine blade root receptive slots provided within and extended axially and fully across the outer peripheral edges of said discs; said slots of respective discs being axially alignable as said discs are secured together, a plurality of turbine blade members each having a blade section and a root section of a size spanning said discs as secured together, said slots and the root sections of said blade members being cooperatively formed for radial locking engagement therebetween, locking projections provided on opposite sides of said root sections and centrally thereof, and said slots being formed adjacent only one face of said discs for close fitted reception of said projections and for axial locking engagement of said root sections thereby as said discs are secured together with the receptive ends of said slots next adjacently disposed.

References Cited in the tile of this patent UNITED STATES PATENTS 532,232 De Laval Ian. 8, 1895 1,073,623 Owen et al Sept. 23, 1913 1,118,361 Lasche Nov. 2A, 1914 1,263,448 McFarland Apr. 23, 1918 2,657,008 Atkinson Oct. 27, 1953 2,685,405 Stalker Aug. 3, 1954 2,819,869 Meyer Jan. 14, 1958 2,844,354 Warnken July 22, 1958 2,848,190 Barr Aug. 19, 1958 FOREIGN PATENTS 134,184 Australia Sept. 7, 1949 

